Hello! This is a fanfic I thought of while reading another Midsomer Murders fanfic that had Welsh in it.
Author note, I am a native welsh speaker. Born and bred in Wales so I know what I'm saying haha. Hope you enjoy.
PS The translations will be at the end.
Also I have now been on fanfiction for 5 years! Whaaaaat!? So this is also a celebratory fanfic, enjoy.

Ben Jones walked into the office he shared with John Barnaby with a spring in his step and a wide grin on his face. Yesterday, him and Barnaby had closed a difficult case that led them on a wild goose chase all over Midsomer. After that case, they both need cheering up while doing the dreaded paperwork, so Ben had hatched a plan on his way to work and he was about to put it into action

"Bore da, syr" Ben exclaimed sitting down in his chair.

Barnaby spun round to face Ben with a very surprised yet confused look on his face. "Pardon?"

Ben giggled to himself "Sut ydych chi heddiw ar y bore hyfryd yma?"

Barnaby's eyes widened with disbelief "Excuse me Jones?!"

"Mae llawer o waith papur I wneud oes na" Ben grinned uncontrollably.

"Jones, what in the world…" Then it clicked, Ben was speaking in his native language. "Jones, for your information I do not speak or understand Welsh"

"Rwy'n gwybod. Dyna pam rwyf yn siarad e"

Barnaby shook his head and turned back to his paperwork. Ben chuckled and did the same. This was going to be an amusing day.

Later on, after several sheets of reports, Barnaby was in need of a strong cup of coffee. He got up from his desk and stretched "You want a cup of coffee, Jones?" he asked

Ben smiled "Wrth gwrs. Dau siwgr fel yr arfer"

Barnaby looked bewildered "I'm going to take that as a yes then" Barnaby swiftly left to get the drinks before Ben could say anything else.
He shortly returned with two hot cups of coffee and placed Ben's on the desk.

"Diolch yn fawr iawn, syr" Ben thanked, taking a sip of the hot beverage.

"Jones, teach me" Barnaby blurted out.

Ben nearly spat out his drink "Eh?"

"Teach me some Welsh, what else do you think I was implying?"

Ben was a bit taken aback by this request from his boss but soon a big grin came across his face "Ok then, let's start with… Llanfairpwllgwyngyllgogerychwyndrobwyllllandisiliogogogoch"

Barnaby's mouth was a gape and was at a loss for words. Ben wished he had a camera because Barnaby's face was priceless.

"Jones! What?" was all Barnaby could manage to say.

Ben lost it and started laughing his head off "That is the name of a place in Wales"

"I was thinking more along the line of teaching me what Police Station was in Welsh, not whatever you said"

"Police Station is Gorsaf Heddlu" Ben had managed to stop laughing by now.

"I think I'll pass on Welsh lessons, Jones" Barnaby gulped down his coffee that he definitely needed now.

Translations:
Bore da, syr – Good morning sir
Sut ydych chi heddiw ar y bore hyfryd yma – How are you on this fine morning
Mae llawer o waith papur I wneud oes na – There is a lot of paperwork to do isn't there
Rwy'n gwybod. Dyna pam rwyf yn siarad e – I know. That's why I'm speaking it
Wrth gwrs. Dau siwgr fel yr afer – Of course. Two sugars like the usual
Diolch yn fawr iawn – Thank you very much, sir